MedifocusHealth

Cancer chemotherapy refers to the use of drugs called antineoplastic agents or chemotherapeutic agents to treat or prevent the recurrence of cancer. Cancer chemotherapeutic agents may be administered by various routes:

• Systemically - the drugs may be injected into a vein (intravenously)
• Orally - the drugs may be taken by mouth
• Locally - the drugs may be injected or implanted directly into a tumor

In general, cancer chemotherapy may be used at various points during the course of the disease:

• Primary chemotherapy - chemotherapy may be the primary or major type of treatment for the cancer and may be started immediately after the diagnosis.
• Adjuvant chemotherapy - chemotherapy that is used as a second form of treatment in addition to another form of primary therapy, such as surgery or radiation therapy.
• Neoadjuvant chemotherapy - chemotherapy that is given before another type of primary therapy, such as surgery or radiation therapy, is started.

In the case of patients with glioblastoma multiforme, chemotherapy is often used in the adjuvant setting as a second form of treatment after the tumor has been surgically removed in order to prevent recurrence of the tumor.

There are two major categories of chemotherapeutic agents that may be used for the treatment of glioblastoma multiforme:

• Cytotoxic agents - these drugs are toxic to cancer cells and cause the cells to die.
• Cytostatic agents - these drugs inhibit or interfere with the growth of cancer cells and prevent them from spreading but are not toxic to the cancer cells.

In the treatment of glioblastoma multiforme, chemotherapeutic drugs may be used alone (single agent chemotherapy) or two or more drugs may be used together (combination chemotherapy).

Currently, a variety of chemotherapeutic options are available for the treatment of glioblastoma multiforme.

Commonly used first-line cytotoxic agents include:

• Temozolomide (Temodar; Temodal) - Recently, this drug has become one of the most common first-line cytotoxic agents used for the treatment of glioblastoma multiforme. Temozolomide is administered orally and is usually better tolerated than some of the other cytotoxic agents. Major side-effects of temozolomide include:

  • headaches
  • nausea
  • fatigue
  • myelosuppression - suppression of the bone marrow's ability to produce blood cells and platelets.

• BCNU (Carmustine) - This drug is a first-line cytotoxic agent that has been a mainstay of chemotherapy for glioblastoma since the 1970s. BCNU is given intravenously and results in high concentrations of the drug within the brain tumor. Major side-effects of BCNU include:

  • nausea
  • fatigue
  • myelosuppression
  • restrictive pulmonary disease - reduction of the total volume of air that the lungs are able to hold resulting in shortness of breath and a dry cough

• PCV - This is a combination chemotherapeutic regimen that combines three drugs: procarbazine, CCNV (Lomustine), and vincristine. The first two of these drugs are given orally while vincristine is administered intravenously. PCV chemotherapy has similar side-effects to BCNU but may also cause peripheral neuropathy - numbness or tingling in the hands and feet due to the toxic effects of vincristine on the peripheral nerves.

Second-line cytotoxic agents are often used for the treatment of glioblastoma multiforme in patients who do not respond to the first-line drugs listed above. Examples of second-line cytotoxic agents that may be used include: